Involuntary leakage of urine is a very common disorder. Urinary incontinence is not life-threatening but it has a strong negative influence on Quality of Life.
About 10% of the population, mostly children and elderly people, have an insufficient control of their urinary bladder. The great majority of these have a minor degree of incontinence allowing them to lead a good life with the aid of simple measures such as a small incontinence pad or frequent change of underwear. The rest, about 1% of the population, have a more severe incontinence that poses a serious social problem. Young people who are physically impaired regard the incontinence as a more severe handicap than the inability to walk. The urinary incontinence is considered to be the most serious obstacle for the creation of lasting relationship to other people, for their ability to live an independent, life, and for their adaptation to the society both on the private and the professional level.
The more serious forms of urinary incontinence are caused by congenital malformations of the bladder or the nerves to the bladder (e.g. myelomeningocele), or traffic accidents with injury to the spinal cord, or pelvic floor damage at child birth, or infections of the nervous system (such as encephalitis or meningitis). Furthermore, several of the diseases of old age, such as prostatic hyperplasia of Parkinson's disease, may cause urinary incontinence.
Generally, urinary incontinence is caused either by involuntary contractions of the bladder muscle (so called unstable bladder), or by insufficient contraction of the urethral sphincter muscle. Unstable bladder can be treated with medication or bladder training with good results. The situation is more problematic when the incontinence is due to a weak or damaged sphincter muscle. So far, there is no medication available that can increase the contraction of the sphincter without giving at the same time unacceptable side effects. The only efficient treatment today for severe cases is operation whereby an artificial sphincter is implanted around the bladder neck or urethra, controlled by the patient via an implanted pump system. This is major surgery, the cost is high (in Sweden at least SEK 100 000), the operation is unsuccessful in 15-25% of patients, and the device has a limited life span, meaning that reoperations will have to be performed in order to exchange components that have broken down. Therefore, many patients choose to keep their severe incontinence instead of going through a major operation with uncertain prospects.
Less than 1/1000 of the population have urinary incontinence due to a faulty sphincter muscle, the most severe and therapy-resistant form of incontinence. Still, this kind of incontinence is found in millions of patients on a global scale.
Since many years, the medical profession has been searching for alternative ways to treat patients with an incompetent sphincter muscle. Some center (Munchen, San Francisco) try esoteric and costly methods, such as transplantation of muscle or implantation of electrostimulators. Plugs or valves have been developed (e.g., U.S. Pat. Nos. 4,679,546 and 4,643,169) for implantation in the urethra, but previously used methods and materials have caused urinary stone and infection, so these devices have been abandoned. However, the development of biocompatible materials during recent years has improved the chances for prolonged survival of an artificial valve within the urinary tract.
Therefore, the main purpose of the present invention is to develop a valve for placement in the urethra or any other emptying tube channel in humans or animals and to construct the valve so that it is well tolerated by the patient's urethra.
The valve is intended to be changed regularly, for instance every 6 months, in order to prevent the development of urinary stone and infection. Furthermore, the pressure within the device keeping the valve in adequate position within the urethra is calibrated so that the valve is well tolerated by the mucous membrane of the urethra but at the same time allowing the entire device to be expelled out of the patient's body in case the bladder pressure would rise to dangerous levels if the opening of the valve would be impaired, thus enhancing the safety of the valve.
Said object is achieved by means of a valve in accordance with the present invention, which is characterized essentially in that a valve body accommodated internally within a valve housing is formed by a permanent magnet, in conjunction with which a stop is situated at the inward-facing part of the valve housing, and in that drainage holes extend to the area of the central part of the valve housing and the central channel of the valve housing to permit urine to be emptied through the valve in its inserted position, and to seal the valve with the valve body in its extended position, and it that the valve is so arranged as to be positioned in the urethra, etc., and to be withdrawn from it with the help of a tool capable of being accommodated in the urethra and activated from the outside of the patient's body, in that the valve is retained in the urethra by means of holding devices with a sealing and retaining effect around the periphery of the valve, which devices are formed from self-expanding bodies, and in that the valve is adjustable from the outside of the patient's body for the purpose of achieving emptying of the urine bladder, etc.